A simple method of percutaneous fine needle aspiration biopsy of malignant lesions in and around the pancreas following radiological localization is described. Biopsy was performed in 28 patients. Twenty-three were eventually considered to have malignant disease and biopsy was positive in 19 of these (83%), including 16 of 18 patients with carcinoma of the pancreas (89%). One patient developed an exacerbation of pancreatitis following the procedure. Surgery became unnecessary in 5 of the 18 patients with positive biopsies. From these results and from a review of the literature on percutaneous fine needle aspiration biopsy, we believe that this is a simple, relatively painless, reasonably safe and reliable method of obtaining a preoperative diagnosis and advocate the procedure as desirable in all patients in whom malignant disease is suspected and can be localized radiologically.